Stove



UNITED STATES PATENT OFFICE.

DENNIS G. LITTLEFIELD, OF LOWELL, MASSACHUSETTS.

STOVE.

Specification forming part of Letters Patent No. 10,448, dated January 24, 1854; Reissued November 19, 1861, Nos. 1,236 and 1,237.

provements attached, the doors being open to show the interior. Fig. 2, a vertical section through the same. Fig. 3 a view of one of the doors; and Fig. 4 a plan of the conical grate.

.Stoves .for burning anthracite .have been contrivedTv inxwhich a .reservoir for the coals has .been applied immediately Aover the .fire

pot in suclr a position .that as the fuel is consumed, .thatin .the reservoir descends `and tion :has italrenplace entirely ,Within .the .lire pot, which .in .no .cases-.has been perforated supplies .itsplace In .such .cases the Vignil to'y permit ,the iflame lto pass through .intof anotherchamber surrounding fthe Afire p ot,

`wherewthe unconsurned .gases might .be .1g-

nited .in contact 4with the `.partially -burned coal and :the .consequence has been that al large .portion of .the .gases `produced have: passedo unconsurned, causinga greatwaste g .of ifuel,...whi1'e -the partially `lconsumed coals from .which .the .more .volatile and'fsinflam-4 mable portions have been expelled, when.

they reachathejnteriorisurfaoe of thepot .or

the` sides ofvthe close.,fireibox*` are soon; cooled A and extinguished, 'the ,current of air whichl makesiits way uptthrough :the lfire being suilcient to keep-thelcombust1onto ay point;

that. would consume all the .binders ,and

morerefractony ipo-LtQns..of .the coal, unless .thefre were rushed,y .whenother inconveniences vresult such .as :theformation of clinkersf Yand the destruction off .the fire po'tz-,the stovein-.such case requiringrea quentlyitobe cleanedx out to .rid-it of ,these clinkersiand unoonsumedicoals.l vOn this ac`v with-,or ...without a reservoir .for fuel, gto.

maintainlthe lire .for `a .considerable ,lengthV ofgtime ,without lthe necessity of `clearing it .is Athe object of my invention, which consists in the employment of a cylindrical grated fire pot, with no solid or unperforated sides, against which the partially consumed coals can rest and cool, which cylindrical grate is surmounted by a reservoir for the recep tion of the gases which arise from the burning of the fresh coal. As this reservoir, which serves also to contain a supply of fuel, is closed at the top t-he only escape for the gases which it collects is through the cylindrical grate at a point -where the solid uncon-Sumed coal is in a state of ignition, these gases are thus inflamed and by the heat thus produced, aid in the combustion ofl the partially consumed coals which always and under the most favorable circumstances burn muchmore reluctantly than the Ifresh coal, as their most inflammable elements have already been dissipated. By carefully collecting ythese gases in the manner above described and igniting them in immediate contact with the unconsurned portions of the coals I am enabled entirely to consume the latter at the same rtime .that the otherwise waste gases are economized and the fuel is consequently ent-irelyI utilized, the ashes falling from the grate at the bottom free from cinders and clinkers. ThisV 'latter peculiarity of my stove, viz, the entire freedom from clinlers, is believed to be due tojthe fact that the hottest part of the fire vis upon the exterior, all around the grate, as this is thepoint where the gases are burnedl `and not as `in all other stoves with whichl am acquainted, in the center. vThe heat is thus kept all through .the re pot at v a heightsuicient to promote constant conibustion. .In stoves as heretofore constructed however the heat accumulates in the center 4of the fire, while atthe sides where it comes in contact with vthe surface f of the fire pot, the coals are cooled so rapidly that they are soon extinguished, and the consequence is a great amount of cinder, which renders it necessary frequently to clean out the stove and start the fire afresh.

In conical grates as heretofore constructed the radial bars pass directly from the center to the circumference and the ashes and small cinders become arched over the openings between the grate bars and thus slide down the latter without being materially disturbed on their way down.

In my improved grate the bars instead of being continuous fromthe center to the circumference are interrupted by two or more rings, and the short bars which unite these rings are so arranged, that those upon one side of the rings are placed opposite to the spaces upon the other side, and thus the cinders are prevented from arching or if the arch be formed it is immediately broken up as the cinders descend along the bars of the grate.

To enable others skilled in the art to make and use my inventio-n I will proceed to describe its construction and operat-ion.

A is the base of the stove immediately above which is Ythe ash pit B.

D is the bed plate having a cylindrical opening in its center' over which are placed the grate and fire pot which rest upon a ringa of the form represented in Fig. 2. The flange b rises a short distance above the bottom of the fire pot, which distance should be slightly less than the average diameter of the coal to be burned and consequently varies with the size of the latter. The fire Apot or cylindrical grate E rests immediately upon a ledge ofthe ring a. The bars d of the grate are of a peculiar shape being Wider at the top than at the bottom so that the spaces c between them are widest at the bottom. This form of the grate bars, though not absolutely requisite, is highly important to the most successful operation of my stove, as the flame of the burning gases is thrown thereby much lower than would be the case if the sp-aces were widest at top, and the hottest part of the fire is thus always at the bottom of the grate and at the exterior which is the reverse of what ordinarily takes place.

The height of the bars of the cylindrical grate should be proportioned to the circumference of the latter, for should this height exceed a certain limit the coals when they reach the bottom of the grate would be too far removed from the influence of the burning gases and thus the object of my invention would be defeated.

F is a reservoir which is placed immediately over the fire pot, to the top of which it is accurately fitted. The main object of this reservoir is to afford a receptacle for the waste and unconsumed gases, which are thrown ofi' during the first ignition of the anthracite and which in stoves as at present constructed pass off through the smoke flues unconsurned. This reservoir also serves the purpose of a magazine or receptacle for the fuel, where it is desired to feed the fire but once in twenty-four or forty-eight hours and if suliiciently enlarged may be made to contain a supply for a. much longer period, The reservoir is furnished with a cover H, which is closed when the cover is in operation. Surrounding the above described cylindrical grate is another cylinder L, which forms the exterior of the stove and between which and the fire grate is the fire chamber G. It is in this chamber that the gases are burned as they issue through the open ings between the grate bars d. It has openings f upon every side, which like those in the doors are glazed with isinglass, and thus the stove when in operation presents the cheerful appearance of an open fire, a large sheet of flame issuing constantly from between the grate bars. The exterior cylinder of the stove is furnished with a cover I, which is to be removed when the reservoir is to be replenished. Y

K is the smoke discharge pipe.

In Fig. 3 is seen a representation` of the sliding doors which are shown open at M, Fig. 1. g are sliding draft doors through which air is admit-ted beneath the grate and by opening or closing which the intensity of the fire is regulated. In order to produce a tight joint between the door and the stove and at the same time to permit the former to slide freely in the grooves which hold it, the bottom of the door is slightly sloped off from the center h, (Fig. 3,) to both corners i, which gives it the required tendency to hang inward. This will appear from an inspection of Fig. 3, for as the dooris curved to correspond with the cylinder of the stove, its center of gravity will fall within the curve, consequently when it rests upon the point L its tendency will be inward or toward the stove. 1

In Fig. 4 is seen a plan of my improved conical grate. 7c k are rings'concentric with the exterior circle of the grate. The bars Z from the center to the ring lc are opposite to the spaces between thevrings k and c, which again fall opposite to the bars of the outer course, and the arching of the cinders over the spaces between the bars is thus prevented as before stated.

Operation: The lire is kindled within the cylindrical grate E, the reservoir is filled with coal and the cover I is closed. The interior cover may be left open a short time until the fire is kindled to prevent smoking the isinglass in the sides of the stove. It is then also closed. As the combustion continues the fuel sinks down, all within the fire pot below the top of the grating being fully ignited, having parted with its more inflammable portions while subjected to the heat of the fire, immediately above the top of the spaces in the cylindrical grate. At this point, about the line w of Fig. 2, the coal is fully ignited, although the combustion is very slow until in descending it reaches the top of the spaces c, when it begins to consume freely. The gases and products of imperfect combustion which were collected within the cylindrical grate being poured out through the spaces in the pot are inflamed and thus aid in the combustion ofthe remaining portions of the fuel, which as before stated always burns reluctantly unless subjected to a great draft, and is easily extinguished when it is allowed to rest against the unperforated sides of an ordinary fire pot. By perforating this fire pot or making it of grating and causing the combustion and draft to be through the spaces in the grating, and by forcing the unconsumed gases to be ignited in ,contact with the coal, both are entirely consumed and the various deleterious gases, which so often poison the atmosphere of our buildings when heated with anthracite, are thus entirely consumed and a great economy of fuel results. In open grates more or less of these unhealthy gases escape into the room, and in close stoves, where the combustion is always more or less imperfect, they pass olf through the smoke flues.

Thus far my invention has been described in its applicability to stoves for heating purposes only. I do not however intend to limit myself to this use of it alone, but to employ it wherever it may be advantageously applied, particularly to house furnaces, cooking ranges, steamboat boilers, Sac. In the latter case the grate bars might all be kwater spaces or the re pot could be made of tubes communicating above and below with the boiler, these are details however which will hereafter be determined and need not now be dwelt upon.

Itis evident that it is not essential that the fire pot be cylindrical, though this is the form which I prefer. It may be of any other form, oval square, &c., provided the essence of the invention remain the same, viz., the grated fire pot with the combustion upon both of its sides, together with any suitable receptacle to collect the gases and to throw them upon the burning coal.

What I claim as my invention and desire to secure by Letters Patent is- The cylindrical grated fire pot E in combination with the gas receptacle F, constructed and operating in the manner substantially as described, by which I am enabled to burn the gaseous and more inflammable elements of the coal in immediate contact with its more refractory portions, .and thus insure the complete combustion of them both.

DENNIS G. LITTLEFIELD. Witnesses:

SAM. COOPER, H. B. SPINNEY.

[FIRST PRINTED 1913.] 

